Widely-tunable (>100 nm) continuous-wave narrow-linewidth high-power thulium fiber laser

Eye-safe, high power, tunable, narrow linewidth lasers are key technologies for a number of applications, including atmospheric propagation measurements. Since the atmosphere has narrow line transmission windows it is important to have a tunable linewidth source which can be matched to the transmission window. We have developed a stable narrow-linewidth (0.3 nm), tunable (from 1947 nm to 2108 nm) large mode area thulium doped fiber laser. Using this as a seed source, a master oscillator power amplifier with similar to 100 W output power will be presented.